Intraosseous vascular lesions are rare conditions, comprising only 0.5% to 1% of all intraosseous tumors. They present with variable and atypical radiographic appearances. Because of this variation, no pathognomonic sign exists that can be used to make a definite clinical diagnosis of these tumors. But, early diagnosis of central hemangioma is essential for preventing uncontrollable hemorrhage and even death during biopsy or surgery. The purpose of this article is to stress on the importance of radiology in the timely diagnosis of such lesions, which can prevent the disaster not only to the patient but also to oral surgeon in legal and professional aspects.

Hemangioma is a benign vascular neoplasm of endothelial origin. [1] Intraosseous hemangioma is an extremely rare condition, constituting about 0.7% of all intraosseous tumors [2] with rare occurrence in the jaws. [3] These lesions of the bone have been referred to as "the great mimicker" because they can produce many different radiographic images. [4] As the radiographic presentation can be misleading, biopsy of such vascular lesions or even a simple tooth extraction without a prior knowledge can result in a catastrophic hemorrhages leading to death.

Here, we report a case of central hemangioma occurring in the mandible with rare presentation of sunray appearance and a brief review on role of radiology in diagnosing such cases.

Case Report

A 75-year-old female patient reported to our institute with the complaint of swelling on the right side of mandible since 5 yrs. Patient presented a history of gradual progress in the size of the swelling; however, rapid growth was reported since 2 years. No other associated symptoms were reported.

Examination revealed a solitary diffuse swelling on right lower third of the face [Figure 1]. The swelling was non-tender and bony hard in consistency. No cervical lymphadenopathy was present. On intraoral examination, obliteration of the buccal sulcus was noticed.

Figure 1: Clinical photograph of the patient showing swelling in relation to the lower third of the face on the right side

Panoramic view revealed an expansile lesion in the region of ramus and body of the mandible on the right side. Anterior aspect of the lesion revealed sclerotic, well demarcated border. The interior of the lesion showed trabeculations radiating from the center to the periphery indicative of "sunburst pattern." The radiating pattern extended beyond the outline of alveolar ridge in the retromolar area, suggesting expansile nature of the lesion. The lesion appears to have extended over the outline of the lower border of mandible. The posterior aspect showed multilocular pattern overlapped by radiating trabeculae [Figure 2].

Posterior anterior view revealed well defined expansile lesion with sunburst pattern in relation to the right side of the mandible [Figure 3].

Figure 2: Orthopantomograph of the patient showing sunburst pattern of the trabeculae in relation to the right side of the mandible

Biopsy procedure was carried out under local anesthesia from the intraoral site (retromolar area). Excessive bleeding encountered during surgical exploration. Two bony fragments removed with chisel. Hemostasis achieved and closure done with 4-0 monocryl. Multiple sections showed bony tissue with lesion. The lesion is composed of proliferating capillaries and few large vascular spaces filled with blood within the marrow spaces and cortical bone. Few cartilaginous fragments are also made out. No evidence of malignancy was detected. Features were consistent with diagnosis of central hemangioma [Figure 4]. Due to the extremes of age and minimal asymmetry, further surgical exploration of the lesion was not considered, and the patient was kept on a periodic follow-up.

Figure 4: Pictomicrograph of the lesion (HandE, 10X) showing proliferating capillaries and few large vascular spaces filled with blood within the marrow and cortical bone. Few cartilaginous fragments can be noticed

Central hemangioma of the jaws is an uncommon lesion that is often difficult to diagnose. Biopsy or surgical excision of lesion can result in severe hemorrhage, which poses a risk of lethal exsanguinations of the patient to the point of death; therefore, a correct clinical diagnosis is desirable before any surgical intervention. [3]

The origin of central hemangioma is debatable. Some believe that it is a true benign neoplasm, while others state that it is a hamartoma stemming from proliferation of mesoderm cells that undergo endothelial differentiation and subsequently are canalized and vascularized. [1],[5] Malignant transformation of central hemangioma has been reported in some cases. Most central hemangiomas are the cavernous type (large-caliber vessels) as seen in the presented case, but can be the capillary type (small-caliber vessels). [5]

Mandible is a very infrequent location [1] although when detected in the mandible, the greatest frequency of occurrence has been the body region, but condylar tumors have also been reported. [6] In our case, similar location of occurrence was observed. It is usually asymptomatic although patient may present with signs and symptoms of slow-growing swelling of the bone, which may or may not cause facial asymmetry. [6] Other features include discomfort, oozing or pulsatile bleeding from the gingiva of teeth in the region of the lesion, mobile teeth, and accelerated exfoliation of teeth. [7] In lesions with high vascular pressure, patients often report a sensation of pulsation, and large lesions extending into adjacent soft tissues may have audible bruits. [7] Despite the benign nature of the lesion, paresthesia in the region is not uncommon. It is crucial to report that patients may not demonstrate any signs or symptoms. Failure to arrive at correct clinical diagnosis of an intraosseous hemangioma surgical intervention may lead to significant hemorrhage and even death. [3]

Intraosseous hemangiomas possess a varied radiographic appearance usually complicating the initial diagnosis. In most cases, the radiographic appearance is certainly not pathognomonic, and only a working diagnosis of central hemangioma of the bone can be made from radiographs. Nearly any combination of lesion shape, location, and pattern can develop. [5]

Early lesions may not be visible on radiographs. In some cases, the lesion produces an alteration in trabecular pattern, which may be thin or lost in some areas, while in others, it can be thicker or coarser. [8] A Zlotogorski et al. has described the borders as well defined in 32% and diffuse in 68% of the 41 cases studied. [9] The literature is inconsistent regarding radiographic borders of the lesion. According to some researchers, lesions are often well-defined, but a corticated border is a variable feature. Others claim that borders may be well-defined and corticated, or ill-defined, simulating a malignant tumor. [9]

Unilocularity, multilocularity, and heterogeneous degree of radiolucency are possible. In about 50% of cases, a multilocular appearance of honeycomb [8] type can be detected that result from fine trabeculations within a loculation. Less commonly, a soap bubble and tennis racket appearance have been reported. [10] A different manifestation of central hemangioma in the jaws consists of a unilocular appearance. [9] These corticated cyst-like spaces are visible because of alignment of vessels in the direction of X-ray beam. [5] In the present case, a rare manifestation of cavernous hemangioma was seen, which appears as cortical destruction with radiating bony spicules, arranged in a sunray pattern. [9] Worth described a pattern whereby the trabeculae are arranged in a manner resembling spokes of a wheel radiating outward from the center of the lesion towards the periphery. The periphery is rounded, irregular, and usually not well-defined. [5]

Hemangiomas can influence the growth of bone and teeth. The involved bone may be enlarged and have coarse internal trabeculae. Also, developing teeth may be larger and erupt earlier when in an intimate relationship with hemangioma. [4] A multilocular appearance may result from serpiginous deformity of mandibular canal. The canal may also be enlarged along its entire length. Hence, it is important to examine carefully the relation of the lesion to mandibular canal to help with differential diagnosis. [4] Enlargement of mental foramen has been noted in some cases. [5]

Osteosarcoma produces similar sunburst appearance as in the present case. It may be entirely radiolucent, mixed radiolucent - radiopaque, or quite radiopaque. There may be asymmetric broadening of periodontal ligament space and onion skin growth of periosteal bone. Irregular margins of a lesion raise a question of malignant tumor like osteosarcoma. [4]

Gibilisco suggests that bony spicules can be seen to extend at right angles from the bone into the lesion with the surrounding bone intact, a feature that is pathognomonic of hemangioma. He mentioned this feature in cavernous hemangioma of the maxilla. When present, this feature serves to differentiate it from ameloblastoma, odontogenic myxoma, and other lesions that may have a honeycomb appearance but, unfortunately, it is not a consistent finding. [5]

Central hemangioma with areas of increased radiopacity can be mistaken for ground glass appearance of fibrous dysplasia. The other radiolucent patterns of central hemangioma can be misdiagnosed as intermediate stages of fibrous dysplasia, but this lesion does not show sunburst appearance. [3]

Multilocular regions of rarefaction that accompany expansion and thinning of the cortex may mimic a central giant cell granuloma of the jaws. However, some investigators believe that loculations produced by a central hemangioma are smaller with fine fibrillar network. [4]

Cystic lesions are more difficult to diagnose radiographically, and an aneurysmal bone cyst may be suspected, but radiographically, this lesion does not resorb the adjacent teeth. Also, this neoplasm lacks the multiple non-corticated foraminae that are sometimes seen in central hemangiomas and arteriovenous malformations. [7]

Central hemangioma, like multiple myeloma, may also present with punched out radiolucencies, but multiple punched out skull lesions are highly characteristic of the latter. Mandibular lesions of multiple myeloma are well delineated without a cortical outline. Perforation of the cortex is more common than expansion. Since hemangioma of bone occurs early in life, the lesion can be in close proximity to the erupting teeth and it can be mistaken for a dentigerous cyst. In contrast to hemangioma, a dentigerous cyst will be associated with a well corticated pericoronal radiolucency attached to the cemento-enamel junction of impacted tooth. [5]

According to Langland et al., [2] a difference in vertical depth of the mandible from one side to the other is suggestive of central hemangioma, but it may be seen also in lymphangioma and neurofibroma. The central hemangioma of bone may be clinically and radiographically indistinguishable from another vascular condition known as central arteriovenous fistula, shunt, or aneurysm. [3]

A definitive diagnosis from the clinical and radiographic features may not be possible without a biopsy. Removal of tissue for microscopic examination, however, carries with it the risk of uncontrollable hemorrhage and should be avoided. Angiography has proved to be a useful diagnostic tool when the features are prompting a diagnosis of heman - gioma. This will be helpful in demonstrating the pressure of the vascular lesion as well as delineating the boundaries and arterial connections. [6]

The choice of treatment depends on the size and location of the lesion, age of the patient, and anticipated problems. The range of treatment includes steroid therapy, carbon dioxide and argon laser therapy, sclerosing agents, irradiation, surgical excision with and without ligation of vessels, and embolization. [3]

The rareness of intraosseous hemangiomas is equaled only by the morbidity they cause. As central hemangioma is characterized by marked variability of its radiological features, it is important on the part of dental practitioners to be aware of the various radiographic patterns, such as the spoke-like and sunray appearance, even though they are extremely rare. A high degree of suspicion leads to their diagnosis and considerably reduces the risks of a catastrophe once identified.